Field of the Invention
The present invention relates to a piece (sample) used for accurately measuring transmittance, e.g. internal transmittance (spectral transmittance excluding reflection loss), of optical materials such as multicomponent glass, synthetic silica glass, and crystal materials as well as a method of making such a piece in particular, it relates to a piece for measuring the transmittance of multicomponent glass used in visible-ultraviolet optical systems, such as g-beam (436 nm) and i-beam (365 nm) lithography techniques and synthetic silica glass and crystal materials used in ultraviolet optical systems in the range of 300 nm or less such as KrF (248 nm) and ArF (193 nm) excimer laser lithography techniques.
Related Background Art
An exposure apparatus called "stepper" has conventionally been used in a photolithography technique in which a fine pattern of integrated circuits is exposed to light and transferred to a wafer made of silicon or the like. The wavelength of the light source of the stepper has been becoming shorter as the integration of LSI increases.